Field of the Invention
The disclosed and claimed concept relates to an alignment assembly for a forming machine and, more specifically to an alignment assembly that repositions a shell from an initial alignment position to an intermediate alignment position between an upper tooling assembly and a lower tooling assembly.
Background Information
Metallic containers (e.g., cans) for holding products such as, for example, liquids, beverages, or food products, are typically provided with an easy open can end on which an opening mechanism, such as a pull tab, is attached (e.g., without limitation, riveted) to a tear strip or severable panel. Typically, the tear strip is defined by a scoreline in the exterior surface (e.g., public side) of the can end. The pull tab is structured to be lifted, pulled, and/or rotated to sever the scoreline and deflect the tear strip, thereby creating an opening for dispensing the contents of the can.
When the can end is made, it originates as a can end shell, which is formed from a sheet metal product (e.g., without limitation, sheet aluminum; sheet steel). The shell is then conveyed to a conversion press, which has a number of successive tool stations. As the shell advances from one tool station to the next, conversion operations such as, for example and without limitation, rivet forming, paneling, scoring, embossing, tab securing and tab staking, are performed until the shell is fully converted into the desired can end and is discharged from the press. Typically, each tool station of the conversion press includes an upper tool member, which is structured to be advanced towards a lower tool member upon actuation of a press ram. The shell is received between the upper and lower tool members. Thus, as the upper tool member engages the shell, the upper and/or lower tool members respectively act upon the public (e.g., exterior side) and/or product (e.g., interior side, which faces the can body) sides of the shell, in order to perform a number of the aforementioned conversion operations. Upon completion of a given operation, the press ram retracts the upper tool member and the partially converted shell is moved to the next successive tool station, or the tooling assembly is changed within the same station, to perform the next conversion operation.
More specifically, a press assembly includes an operating mechanism, a transfer belt, and a tooling assembly. The tooling assembly includes an upper tooling assembly and a lower tooling assembly. In an exemplary embodiment, at each station the upper tooling assembly includes a forming construct such as, but not limited to, a punch. Similarly, at each station the lower tooling assembly includes a cooperative forming construct such as, but not limited to, a die. The shells are moved intermittently, or as used herein, “indexed,” through the tooling assembly thereby stopping at each station. That is, the operating mechanism is structured to operatively engage the transfer belt and the tooling assembly, essentially, alternately. Such an apparatus is disclosed in U.S. Pat. No. 4,903,521.
The transfer belt is structured to index a number of shells through the tooling assembly. In an exemplary embodiment, the transfer belt includes a number of apertures into which a blank is deposited. As noted above, the upper tooling assembly and the lower tooling assembly are structured to move between a first position, wherein the upper tooling assembly and the lower tooling assembly are spaced, and a second position wherein the upper tooling assembly and the lower tooling assembly are disposed immediately adjacent each other. It is common for one tooling assembly to be stationary and for the other tooling assembly to move. In an exemplary embodiment, and as used herein, the upper tooling assembly is described as the tooling assembly that moves while the lower tooling assembly is described as the stationary tooling assembly. When the upper tooling assembly and the lower tooling assembly are not in the second position, the operating mechanism operatively engages the transfer belt to move each shell to the next station. The transfer belt positions each shell in an initial alignment position at a station between the upper tooling assembly and the lower tooling assembly. When the shells are in the initial alignment position at a station between the upper tooling assembly and the lower tooling assembly, the operating mechanism operatively engages the upper tooling assembly and moves the upper tooling assembly to the second position. During this operation, the forming operations as described above occur.
Part of the forming operations may include moving the shell to a final alignment position. That is, a shell in the initial alignment position is often not properly aligned with the forming constructs of the station. Accordingly, the tooling assembly, and more specifically each station, may include a final alignment assembly that is structured to position the shell in the final alignment position. In an exemplary embodiment, a final alignment assembly includes an angled surface on the upper tooling assembly. As the upper tooling assembly moves toward the second position, the angled surface on the upper tooling assembly operatively engages the shell and moves the shell to the final alignment position. Once the shell is in the final alignment position, the forming constructs engage the shell and perform the forming operation(s) of the station.
Such press assemblies have a disadvantage in that a shell in the initial alignment position may be too misaligned to be placed in the final alignment position by known tooling assembly assemblies. By way of example, as the shell is converted from an initial generally planar shape to the final shape, the area of the shell may diminish. That is, a shell begins, in many instances, as a planar member. To accommodate the initial configuration of the shell, the apertures in the transfer belt must have a shape that corresponds to the shape of the planar shell. That is, the size and shape of the apertures in the transfer belt substantially correspond to the size and shape of the initial size and shape of the shell. Forming operations on the shell, such as, but not limited to, forming a curled perimeter on the shell, cause the size and the shape of the shell to change and often results in the shell having a smaller area. Moreover, the indexing, i.e., rapidly starting and stopping the transfer belt, cause a shell to move within the transfer belt apertures. That is, the shells may be displaced forwardly, rearwardly, laterally, or askew, i.e., angularly offset, in the transfer belt apertures.
There is, therefore, a need for an alignment assembly that repositions a shell from an initial alignment position to an intermediate alignment position between an upper tooling assembly and a lower tooling assembly. There is a further need for an alignment assembly that may be incorporated into existing press assemblies.